The present invention relates to a novel stripping liquid composition for easily stripping off positive type photoresist film, negative type photoresist film, or the like formed on an inorganic substrate, without damaging the substrate.
In the manufacture of semiconductor integrated circuits or the device circuit of a liquid crystal panel, fine circuits are formed by applying a photoresist on a conductive metal film such as an Al alloy or an insulating film such as an oxide film formed on an inorganic substrate, exposing and developing the photoresist to form a pattern, and etching the metal or insulating film by using it as mask. Later, when the resist is not necessary, it is removed. As the stripping liquid for removing the resist, the combination of alkyl benzene and alkyl benzene sulfonic acid is widely employed.
As disclosed in the Japanese Laid-open Patent Sho. 64-42653, it is proposed to use alkaline organic solvents such as dimethyl sulfoxide, diethylene glycol monoalkyl ether, and organic hydroxy compounds containing nitrogen, or strong acids such as sulfuric acid and nitric acid.
The Japanese Laid-open Patent Sho. 62-49355 discloses a stripping liquid composition composed of ethylene oxide, an addition product of alkanol amine or polyalkylene polyamine, sulfone compound, and glycol monoalkyl ether.
However, in the combination of alkyl benzene and alkyl benzene sulfonic acid, corrosion is likely to occur, the rinsing process is complicated, and the stripping force is weak. When using the stripping liquid, or strong acids such as sulfuric acid and nitric acid disclosed in the Patent Sho. 64-42653, satisfactory results are not obtained in the stripping force or in corrosion resistance.
In the case of the stripping liquid composition disclosed in the Patent Sho. 62-49355, the stripping force is also weak.
Recently, as the processing size is becoming finer, the etching condition of the metal or the oxide film is becoming more sever the photoresist is heavily damaged, and the resist changes in quality. Accordingly, if treated by the above-mentioned organic solvent, the resist is left over on the substrate, and the stripping liquid composition with a powerful stripping force is demanded.